Re: regarding generic AIO, async syscalls precedent + some benchmarks by lighttpd
Davide Libenzi wrote: Yes, that is some very interesting data IMO. I did not bench the GUASI (userspace async thread library) against AIO, but those numbers show that a *userspace* async syscall wrapper interface performs in the ballpark of AIO. This leads to some hope about the ability to effectively deploy the kernel generic async AIO (being it fibril or kthreads based) as low-impact async provider for basically anything. SGI's kaio patch to linux kind of went that route (using kthreads) for non-SCSI async IO. It wasn't a bad way to go, but at least for disk-based access they achieved much better results when they could go right to the hardware. --Chris - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: regarding generic AIO, async syscalls precedent + some benchmarks by lighttpd
On Sun, 4 Feb 2007, bert hubert wrote: > >From two comments posted to my "blog" > http://blog.netherlabs.nl/articles/2007/02/04/a-synchronous-programming > > Excerpted from the diary of Dragonfly BSD, > http://www.dragonflybsd.org/status/diary.shtml > > Remove the asynchronous syscall interface. It was an idea before its time. > However, keep the formalization of the syscall arguments structures. > > The original async syscall interface was committed in > http://leaf.dragonflybsd.org/mailarchive/commits/2004-08/msg00067.html > > Comment by Jan Kneschke, lighttpd developer, noting the lack of and need for > aio_stat(): > > Reading this article feels like reading the code I wrote in the last days > for lighttpd. Even if the network-io was async since the start > (non-blocking), the file-io wasn't. Worst of all was the stat() syscall > which doesn't have a async interface even in POSIX AIO. So it had to be > implemented with threads on our own. At http://www.lighttpd.net/benchmark/ > you can see the impact of async vs. blocking syscalls. > > Perhaps relevant. Yes, that is some very interesting data IMO. I did not bench the GUASI (userspace async thread library) against AIO, but those numbers show that a *userspace* async syscall wrapper interface performs in the ballpark of AIO. This leads to some hope about the ability to effectively deploy the kernel generic async AIO (being it fibril or kthreads based) as low-impact async provider for basically anything. - Davide - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
regarding generic AIO, async syscalls precedent + some benchmarks by lighttpd
>From two comments posted to my "blog" http://blog.netherlabs.nl/articles/2007/02/04/a-synchronous-programming Excerpted from the diary of Dragonfly BSD, http://www.dragonflybsd.org/status/diary.shtml Remove the asynchronous syscall interface. It was an idea before its time. However, keep the formalization of the syscall arguments structures. The original async syscall interface was committed in http://leaf.dragonflybsd.org/mailarchive/commits/2004-08/msg00067.html Comment by Jan Kneschke, lighttpd developer, noting the lack of and need for aio_stat(): Reading this article feels like reading the code I wrote in the last days for lighttpd. Even if the network-io was async since the start (non-blocking), the file-io wasn't. Worst of all was the stat() syscall which doesn't have a async interface even in POSIX AIO. So it had to be implemented with threads on our own. At http://www.lighttpd.net/benchmark/ you can see the impact of async vs. blocking syscalls. Perhaps relevant. -- http://www.PowerDNS.com Open source, database driven DNS Software http://netherlabs.nl Open and Closed source services - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
regarding generic AIO, async syscalls precedent + some benchmarks by lighttpd
From two comments posted to my blog http://blog.netherlabs.nl/articles/2007/02/04/a-synchronous-programming Excerpted from the diary of Dragonfly BSD, http://www.dragonflybsd.org/status/diary.shtml Remove the asynchronous syscall interface. It was an idea before its time. However, keep the formalization of the syscall arguments structures. The original async syscall interface was committed in http://leaf.dragonflybsd.org/mailarchive/commits/2004-08/msg00067.html Comment by Jan Kneschke, lighttpd developer, noting the lack of and need for aio_stat(): Reading this article feels like reading the code I wrote in the last days for lighttpd. Even if the network-io was async since the start (non-blocking), the file-io wasn't. Worst of all was the stat() syscall which doesn't have a async interface even in POSIX AIO. So it had to be implemented with threads on our own. At http://www.lighttpd.net/benchmark/ you can see the impact of async vs. blocking syscalls. Perhaps relevant. -- http://www.PowerDNS.com Open source, database driven DNS Software http://netherlabs.nl Open and Closed source services - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: regarding generic AIO, async syscalls precedent + some benchmarks by lighttpd
On Sun, 4 Feb 2007, bert hubert wrote: From two comments posted to my blog http://blog.netherlabs.nl/articles/2007/02/04/a-synchronous-programming Excerpted from the diary of Dragonfly BSD, http://www.dragonflybsd.org/status/diary.shtml Remove the asynchronous syscall interface. It was an idea before its time. However, keep the formalization of the syscall arguments structures. The original async syscall interface was committed in http://leaf.dragonflybsd.org/mailarchive/commits/2004-08/msg00067.html Comment by Jan Kneschke, lighttpd developer, noting the lack of and need for aio_stat(): Reading this article feels like reading the code I wrote in the last days for lighttpd. Even if the network-io was async since the start (non-blocking), the file-io wasn't. Worst of all was the stat() syscall which doesn't have a async interface even in POSIX AIO. So it had to be implemented with threads on our own. At http://www.lighttpd.net/benchmark/ you can see the impact of async vs. blocking syscalls. Perhaps relevant. Yes, that is some very interesting data IMO. I did not bench the GUASI (userspace async thread library) against AIO, but those numbers show that a *userspace* async syscall wrapper interface performs in the ballpark of AIO. This leads to some hope about the ability to effectively deploy the kernel generic async AIO (being it fibril or kthreads based) as low-impact async provider for basically anything. - Davide - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: regarding generic AIO, async syscalls precedent + some benchmarks by lighttpd
Davide Libenzi wrote: Yes, that is some very interesting data IMO. I did not bench the GUASI (userspace async thread library) against AIO, but those numbers show that a *userspace* async syscall wrapper interface performs in the ballpark of AIO. This leads to some hope about the ability to effectively deploy the kernel generic async AIO (being it fibril or kthreads based) as low-impact async provider for basically anything. SGI's kaio patch to linux kind of went that route (using kthreads) for non-SCSI async IO. It wasn't a bad way to go, but at least for disk-based access they achieved much better results when they could go right to the hardware. --Chris - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
